Many industrial, research and analytical applications require the use of sealed chambers having controlled atmospheres, e.g. dry or inert atmosphere (i.e., Ar or the like) chambers, high or ultra-high vacuum chambers, chambers held above ambient pressure, dust-free environments and protective chambers such as those used in certain biological research. Vacuum applications include among others sputtering, vapor deposition, plasma etching and ion implantation processes requiring remote positioning, movement or rotation of samples within a vacuum chamber. Applications in scientific research include among others those requiring the positioning of electron, ion or atom sources or nozzles with respect to each other, light sources, detectors, or similar devices within a vacuum chamber. In such applications, it is desirable to position, move or rotate objects within the chamber without opening the chamber thereby compromising its internal atmosphere. To meet these needs positioning devices or manipulators remotely operable from outside the chamber have been developed.
U.S. Pat. No. 4,885,946 discloses a mechanism for feed through of rotary and/or linear motion to a sealed chamber. The feed through mechanism includes coaxial shafts, one held within an opening through the other, which in one embodiment can each carry a sample and rotate simultaneously at different speeds and in opposite directions. In an alternate embodiment, the mechanism can be adapted to rotate a sample and position it within the chamber in one-dimension along the shaft axis. This feed through mechanism relies upon the use of flexible bellows to maintain seals therein to the sealed chamber. U.S. Pat. No. 4,885,947 describes another rotary motion feed through device.
U.S. Pat. No. 5,105,932 discloses a precision magnetically operated manipulator which allows independent sample rotation and single-dimension positioning of the sample by linear motion. The disclosed manipulator comprises a rotatable cylindrical center rod carrying a sample or target supported within a square, linear shaft which is itself supported within a housing. Rotation of the center rod, which is coaxial with the square shaft, with respect to that shaft rotates the sample. Linear translation of the square shaft within its housing positions the sample in a single dimension (coaxially with the shaft) within the chamber. The support housing, square shaft and rod are enclosed in a sealed housing mountable on a vacuum chamber and are all then placed under vacuum. Two magnet carriage systems, one for rotation and the other for translation, positioned outside of the sealed housing, are employed to rotate and position the sample from outside the vacuum chamber.
U.S. Pat. No. 4,850,779 discloses a remotely operable manipulator which carries a rotatable object-holder, i.e., gripping jaws, mounted on a shaft and operated by a sleeve mechanism. Flexible metal bellows sealing units permit axial and lateral movement of the shaft and sleeve to change the position of the object-holder in the chamber.
U.S. Pat. Nos. 4,030,615 and 4,497,053 also disclose manipulators for movement of objects in a sealed chamber. The bellows-type manipulator of U.S. Pat. No. 4,030,615 allows linear displacement, turning and pivoting in three-dimensions of a sample mounted on a manipulating bar. Displacement is conveyed to the manipulating bar by means of an external moveable guide via a ball joint. A flexible bellows mechanism provides a seal to the external atmosphere while allowing motion of the external guide. In U.S. Pat. No. 4,497,053, an externally operable rotary drive mechanism coupled to two internal perpendicular guided slides allows rotation and two-dimensional positioning of a sample mounted on one of the slides.
The present invention provides new remotely operable manipulators that allow three-dimensional positioning of a object and object rotation, if desired, in a sealed chamber. The inventive manipulator design allows accurate object positioning, is simple, inexpensive, rugged and low-maintenance and precludes the need for expensive, thin-walled and failure-prone bellows seals to achieve three-dimensional positioning. The new design is versatile, can be constructed in a variety of sizes and is readily adaptable for manual, magnetic or motor-driven operation.